fix(v2): restore provider license headers

Signed-off-by: Moritz Johner <beller.moritz@googlemail.com>

providers/v2/aws/main.go

@@ -1,4 +1,6 @@
 /*
+Copyright © The ESO Authors
+
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at

providers/v2/fake/main.go

@@ -1,4 +1,6 @@
 /*
+Copyright © The ESO Authors
+
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at

providers/v2/kubernetes/main.go

@@ -1,4 +1,6 @@
 /*
+Copyright © The ESO Authors
+
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at